airplane mode

A setting on cell phones, smartphones and mobile devices that prevent it from sending or receiving calls and text messages. Also slang for when someone cuts themselves off from the world by not checking their smartphone or not logging into social media.
"She's not going to answer your calls. She's in airplane mode."

Historical perspective: The term was coined in October 2013 when the United States Federal Aviation Administration (FAA) made a recommendation on the use of electronic devices in "airplane mode." On an iPhone, airplane mode disables connectivity for cellular voice and data, Wi-Fi, Bluetooth, GPS and location-based services.